On Thursday 9 November 2023 at 19:15 UTC, a HTTP GET flood targeted a developer platform customer in North America. The attack peaked at 779.3 million requests per second and lasted 112 minutes. Traffic originated from 3076 autonomous systems in 108 countries, predominantly a headless-browser farm.
| Vector | HTTP GET flood |
| Peak | 779.3 million requests per second |
| Duration | 112 min |
| Time to mitigation | 0.440 s |
| Attack traffic reaching origin | 0.065% |
| Legitimate traffic challenged | 0.25% |
Timeline
The attack was preceded by a ransom note demanding payment in Monero. Request rates on the targeted routes exceeded their hourly baseline by a factor of 518 within 21 seconds. The risk score of participating clients crossed the challenge threshold automatically and proof-of-work difficulty rose with origin load.
What the customer saw
The customer’s status page stayed green throughout; they learned about the attack from our notification.
Recommendations
- Lower challenge thresholds on authentication endpoints during high-risk events.
- Enable log streaming to your SIEM for faster correlation.
- Add a dedicated rate limit for the targeted route.
How does the proof-of-work challenge behave on older Android devices? Any numbers below Android 10?